Brake



Allg. 16, 1932. K E, LYMAN BRAKE Filed May 2, 1928 Patented ug. 16, 1932 UNITED KENNETH E. LYMAN, OF CHICAGO, ILLINOIS, AS'SIGNOR TO BEND'IX BRAKE COMPANY, 0F SOUTH BEND, INDIANA, A CORPORATION 0F ILLINOIS BRAKE Application led May 2,

This invention relates to brakes and is i1- lustrated as embodied in an internal expanding brake for an automobile. An object of the invention is to provide a simple structure giving a compound Servo action of one brake shoe on another, thus building up the braking effect without additional effort on the part of the driver. y

Preferably the friction means ofthe brake includes a plurality of iioating brake shoes which, in the illustrated form, have an anchorage which shifts when the drum reverses its direction of rotation so that the friction means is always fully effective, and which friction `ineans is so arranged that it includes a plurality of shoes or equivalent devices, one of which acts with a multiplying leverage on the other during the application of the brake. In the arrangement shown there are two shoes which cross each other at one side of the brake drum and which are pivotally connected at the point where they cross and which are provided at their ends with fulcrums or pivots to provide the descrlbedleverage. y

Other features of the invention relate to novel anchoring means for the brake, to de:

sirable details in the construction of stop devices and the arrangement of the springs f or determining the released position of the f rlction means, and to other novel combinations of parts and desirable particular constructions which will be apparent from the following description of one illustrative embodiment shown in the accompanying drawing, in which: -i

The gure is a vertical section through the brake just inside the head of the brake drum and showing the brake shoes in side elevation.

The illustrated brake includes a rotatable drum 10, at the open side of which is arranged a suitable stationary support such as a backing pla-te 12 and Within which is arranged the friction means of the brake.

The illustrated friction means comprises a pair of brake shoes 14 and 16 extended to form lever arms at their lower ends, which arms cross each other and are connected by a floating pivot 18. The ends of the arms beyoud the pivot 18 are formed with slots or 192s. serial No. 274,384.

notches 20 slidably mounted on fulcrums or pivots 22 and 24 having washers 26 held by cotter pins 28 to confine the shoes laterally. A spring 30 is tensioned between the fioating pivot 18 and a post 32 carried by the backing Cplate to urge the shoes away from the brake drum.

The shoes are applied by means such as a floating double cam 34 acting on rollers 36 pivoted on the ends of the shoes, against the `resistance of return springs 38. Shoe 14 is formed with a thrust abutment 40 engageable with an adjustable eccentric anchor 42 while 'shoe 16 is shown provided with a link 44 pivotally connected at one end to the shoe and mounted at its other end on a fixed pivot 46 carried by the backing plate 12. Grooved eccentrics 48 embrace the webs 'of the shoes adjacent their lower ends to confine the shoes laterally and also to serve as stops engaging the edges of the webs to determine the released positions of the shoes.

In applying the brake the shoes 14 and 16 are forced apart against the resistance of the springs 88. 'If the drum is turning clockwise, the shoe 14 pivots about the fulcrum 22 to force the floating pivot 18 in a direction to apply the shoe 16 with an'increased leverage and the torque of both shoes is taken on the fixed pivot 46 through the link 44. As the torque of the brake urges the link 44 in a direction to swing the shoe away from the brake drum, there is no tendency for the brake to grab. If the drum is turning in a counterclockwise direction, the shoe 16 fulcrums on the pivot 24 to force the floating pivot 18 toward the right to apply the shoe 14 and the torque of both shoes is taken on the anchor 42. Thecam 34 is mounted in any de- .sired and well-known'manner to permit it to shift to the right' or left according to the anchorage of the friction means.

`While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of my invention to that particular embodiment or otherwise than by the terms of the 'appended claims.

Iclaim: v 1. A brake comprising at least two floating overlapping shoes connected by a floating pivot intermediate the ends of said shoes, together with a fixed pivot on which one ofthe shoes fulcrums to apply the other. v

2. A brake comprising at least two overlapping shoes connected by a floating pivot, together with a fixed pivot for each of the shoes u on which each may pivot.

3. A rake comprising at least two shoes having extensions forming interconnected crossed levers, together with a fulcrum for each lever upon which the corresponding shoe may turn.

4. A brake comprising at least two shoes having extensions lforming interconnected crossed levers, together with a fulcrum for each lever upon which the corresponding shoe may turn, together with a return spring acting on the interconnected lever portions of the shoes to urge them toward released posi- 5. A brake comprising two oati shoes having crossed parts connected by a oating pivot, means acting intermediate the ends of said shoes to spread the-same apart, together with a fixed pivot on which one of the shoes fulcrums to apply the other.. 1

`6. A brake comprising two floating overlapping shoes connectedby a floating pivot wlthin a revolving drum, said brake adapted to anchor at one or the other of its ends depending on the direction of drum rotation, each of said shoes being applied to the drum simultaneously at two remote points. 7. A brake. comprising two oating overas lapping shoes connected by a floating pivot v within a revolving drum, said brake adapted to anchor at one or the other of its ends dependin on the direction of drum rotation, each o said shoes being applied to the drum simultaneously at each of its extreme ends.

8. A brake comprising, in combination, a rotatable drum, two overlapping friction de vices having spaced apart ends adapted to anchor on one or the other of said ends depending upon the direction of drum rotation,

each of said devices pivotally connected to the other device'by a ioatin'g pivot and one of said friction devices adapted to force the other friction device into drum contact at I0 said ioating pivot.

In testimony whereof, I 'have hereunto signed my name. v

KENNETH E. LYMAN. 

